Hey guys. I got a 87 4x4 that sit about ten months because it had jumped time I got the truck installed timing chain and I've drove it for about 200 miles and all of a sudden it starts smoking Awfull if I drive it just a couple of miles it burns about 1/4 quart I done a comp test and I got 155,150,150,155 so that's good right it did smoke a lil when u start it in mornings but would stop right away. Now it doesn't stop it just sat over night and now it's smokes Awfull so any help be great
Thanks again

 

155-150-150-155 sounds low to me as it should be around 170 with a healthy engine.

 

Leak down test? Burning oil is blow by.

:wabbit2:

 

Ok is 150 low enough to make her burn so much oil and smoke like a freight train.

 

Leak down held good

 

Could valve seals be doing this ?? As it did sit for a while

 

Valve seals could, but rings throw more oil into the cyls.

If it only smokes when your off the throttle or only on startup I would suspect the valve seals, if it smokes whether your under load or not, I would suspect rings.

Did leak down hold good at 170 psi or 150 psi?

Valve seals don't affect compression either ,only valve seats do. This is the purpose of a leak down.

Being that it sit so long there is a god possibility you have a ton of carbon buildup on the valves. Also after sitting the cyl walls get real dry as well and the next startup could very well score cyl walls. It would be like putting a new engine together and not pre-lubing the pistons. Next thing you know the cyl walls get glazed and the rings don't ever seal correctly or you put excessive wear on the cyl walls.

 

It smokes all the time but is alot worse when ur on the pedal

 

Probably a combination of some past the rings and valve stem seals. I'd bet more of a problem with the seals than rings. Check and clean your PCV valve, make sure there's no pressure in the crankcase.

 

Here is a backyard mechanic trick. Now that sb5walker reminded me. Take off your PVC line and block that and also take off the front breather line on the valve cover as well. Drive it. Does the smoke go away? If so the it's either rings or your PCV is simply stuck open. Try a new PCV hook lines back up. Does it still smoke? If not, problem fix, if it still smokes then it's your rings.

Valve guide/seal leaks typically don't smoke full time only on startup since oil leaks down into the cyls overnight and simply burns off quickly. When the engine is running and assuming the valves are sealing properly it's almost impossible to push cyl pressure back into the head through them. However it is possible oil can be sucked in though them, however you would only see this under high vacuum, meaning deceleration and/or when coming off the gas for a short period of time and right back on. However same symptoms can be said with rings as well. But if it also does it right on startup, it would be likely the seals/guides.

 

It's smoking bad and I noticed that all my plugs looked good except number 4 plug it's oily but that cylinder also holds good during a leak down.

 

Oh and I pulled the pcv valve it rattles like it should and I drove it with it plugged off and no diff still smoking Awfull There seems to be a good tap coming from the valve cover? It just blows my mind because it started this overnight Thanks again y'all